Anti-bacteria agent made from shell, and methods for purifying and desalinating water and for washing agricultural products with use thereof

ABSTRACT

For providing an anti-bacteria which is made from a natural material, therefore harmless if it is absorbed in the human body, can be produced in mass production with low cost, and shows a high anti-bacteria effect, the anti-bacteria agent is obtained by heating a shell in an atmosphere of inactive gas and burning the shell under the temperature which finally reaches 700° C. - 2,500° C.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an anti-bacteria agent which issuitable for protecting foods from contamination with bacteria, inprocessed foods manufacturing industry, in food restaurant industry, andat home, and for disinfecting, sterilizing or pasteurizing in medicalindustry and medical welfare industry, and relates to a method fordesalinating and purifying sea water and river water, and further to amethod for washing or cleaning with use of water purified thisanti-bacteria agent.

[0003] 2. Description of Prior Art

[0004] Chemical compound(s) of chlorine was used as a generalanti-bacteria agent. However, it sometimes generated trihalomethane in atreatment of waste water and/or generated dioxin in an incinerating orburning treatment. As examples of anti-bacteria agents, which have beenused as a food additive in farming and fisheries or marine productsindustry, there are synthetic anti-bacteria agent, such as sulfamizin,carbadox, or the like, as medicines for animals. However they must bestrictly controlled, in particular, in residual value thereof to be lessthan a standard value, from a view point of safety of foods.

[0005] Therefore, the anti-bacteria agents made from natural materialsas ingredients, rather than the anti-bacteria agents of chemicalcompound(s) mentioned above are required, in particular, in a field oftreating foods which has a possibility to be taken inside the human bodythrough a mouth. For example, a report “An Effect of Green Tea On O-157”was published by the group of Prof. TeLdakatsu Shimamura, the medicaldepartment of Showa University, and attracted attention of manyconsumers. After this publication, catechin of tea, though it wasconventionally used as a food additive, has come into wide use.

[0006] The catechin of tea, attracting attention as an anti-bacteriaagent made from a natural material, must be extracted from green tea asan ingredient, therefore is not suitable for mass production.Accordingly, a new anti-bacteria agent is required, which is made from anatural material as an ingredient, is harmless when absorbed in thehuman body, can be produced in mass production with low cost, and showsa further high anti-bacteria effect.

[0007] In particular, an anti-bacteria agent which is made from anatural material and is harmless when absorbed into the human body, isconsidered also to have an effect on purification of water. Hereinafter,there are listed examples or cases now in issues.

[0008] First, the desalination of sea water can be listed. In thecountries of the Middle East, freshwater is obtained from sea waterthrough a reverse permeable membrane method, a distillation method, arefrigeration method or an electric dialysis method, etc., in general.When salt etc., is removed from sea water in this manner, bacteria caneasily propagate. Therefore an anti-bacteria agent of Cr group or Clgroup, is added to prevent the propagation of bacteria. However, theagent of the Cr group or Cl group is extremely harmful to the humanbody, and a danger of producing cancer cannot be denied.

[0009] Second, the purification of river water can be listed. In riverwater into which drainage by human life (organic matter) flows, the BODvalue is high, and it generates bad smell.

[0010] Third, washing or rinsing of agricultural products can be listed.To agricultural products after a harvest, an insecticide sometimesadheres. As a result of this, after agricultural products are washedwith a synthetic detergent, they are rinsed with water for general use(i.e., water from a water supply or from rivers), in order to wash suchinsecticide away. However, since ordinary water is poor in anti-bacteriaeffect or power by itself, there is a possibility that bacteriapropagates on the surface of agricultural products until they reachgeneral consumers.

SUMMARY OF THE INVENTION

[0011] For dissolving the problems mentioned above, according to theclaim 1 of the present invention, there is provided an anti-bacteriaagent made from shell. An anti-bacteria agent, according to the presentinvention, is obtained by heating a shell in an atmosphere of inactivegas and burning the shell under the temperature which finally reaches700° C. - 2,500° C.

[0012] As shells, a surf clam is the most preferable, since it isrecognized to have sterilizing power against general bacteria. Howeverit may be any one of an oyster, a scallop, a clam, a turban shell and asnail, if it is burned. By burning, the shell itself comes to be porous,therefore a contacting area is increased, thereby remarkably improvingsterilizing or disinfecting power.

[0013] In particular, a shell powder of a surf clam, by burning in anatmosphere of inactive gas, shows strong and continuous property ofanti-bacteria against germs or bacteria, such as Escherichia coli O-157or the like, even if it is added only a little bit. It is also a naturalmateriel which mainly contains calcium, therefore it is safe for thehuman body. In addition, in a case where it is disposed, it nevercontaminates air, water, or soil. It also brings an effect that shells,which were too much to be managed as waste conventionally, can beutilized effectively.

[0014] If the anti-bacteria agent mentioned above is crushed to have amaximum particle diameter equal to or less than 100 μm and have a meanparticle diameter from 1 μm to 50 μm, it can be easily dissolved intowater (in particular, into warm water), thereby enabling to furtherimprove its anti-bacterial effect.

[0015] The burned shells made from natural material or naturalingredient are described in No. 218 of the list of the existingadditives, which is defined in the revised version of the Food HygieneAct and the Nutrition Improvement Act as burned calcium (which mainlycontains calcium compounds obtained by burning shells or the like). Itis officially recognized to be safe for the human body.

[0016] Accordingly, regarding the anti-bacteria agent according to thepresent invention, it is preferable to be used for protecting foods fromcontamination by germs or bacteria in food service or food restaurantindustry or at home, and for sterilization, pasteurization, ordisinfection in medical industry or medical welfare industry.

[0017] The anti-bacteria agent of the present invention, which isapplied to desalination, is made be contact with freshwater obtainedfrom sea water by using any one of the reverse permeable membranemethod, the distillation method, the refrigeration method or theelectric dialysis method.

[0018] As a result of such structure, it is possible to remove orremarkably reduce the amount of a disinfectant or germicide of the Crgroup or Cl group added to freshwater after obtained from sea water.

[0019] According to the present invention, which is applied topurification of river water, the above-mentioned anti-bacteria agent isfilled into a net (including a case through which river waterpermeates), and the net is provided to be laid within a river.

[0020] The burned shells, in addition to the anti-bacteria function ofitself, come to be porous, therefore bacteria which decomposes organicmatter propagates on the surface thereof, thereby promoting purificationof river water. Further, if river water is increased in a degree of anacidity thereof, the burned shells are dissolved into river water, so asto maintain a pH value within the most suitable range.

[0021] According to the present invention, which is applied to washingof agricultural products, agricultural products such as vegetables,fruits or the like are rinsed with water contacted with theabove-mentioned anti-bacteria agent after washed with syntheticdetergent.

[0022] As a result of this structure, it is possible to suppresspropagation of germs or bacteria on the surface of such agriculturalproducts for a long time period.

BRIEF DESCRIPTION OF THE DRAWING(S)

[0023]FIG. 1 is a block diagram showing desalination processes forobtaining freshwater from sea water;

[0024] FIGS. 2 (A) and (B) show a view explaining a purification methodof river water and a perspective view of a net which is provided to belaid on river floor respectively; and

[0025] FIGS. 3 (A) and (B) are views showing a condition of washingagricultural products and a condition of rinsing after the washing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

[0026] Hereinafter, embodiments according to the present invention willbe fully explained by referring to the attached drawings.

[0027] A surf clam, as an ingredient or raw material of theanti-bacteria agent according to the present invention, is a kind ofbivalves, and it is distributed in the seas around the middle part ofthe main island of Japan and in the northern part of the Sea of Japan.This surf clam is served or used as a canned food, or a frozen or freshfood; however the shell of this is not used effectively. Therefore, thecost for supplying is low.

[0028] To manufacture the anti-bacteria agent of the present inventionfrom the surf clam, first, the shells of the surf clam are crushed. Theshells are dried, and thereafter, they are roughly crushed by means of agrind mill and so on, thereby adjusting to be equal to or less than 5 mmin a maximum diameter thereof.

[0029] Next, the crushed shells are entered into an autoclave equippedwith a stirrer, and burned under an inactive gas atmosphere while beingstirred. The inactive gas is preferably to be nitrogen gas. A method ofincreasing temperature is not in question; however the final temperaturereaches a range from 700° C. to 2,500° C., more preferably, 900° C.±50°C., and the temperature is maintained for three (3) minutes or longer.

[0030] If the final temperature is less than 700° C., it is difficult toobtain the anti-bacterial property. If it exceeds 1,000° C., an activeportion of the particle is broken or destroyed, therefore it is alsoimpossible to obtain the anti-bacterial property. In addition, if theburning time is less than three (3) minutes, it is difficult to obtainthe anti-bacterial property It does not matter if the burning time islong; however it is preferable to be from three (3) minutes to five (5)minutes from a view point of the cost.

[0031] Then, the burned shell particles are cooled under the inactiveatmosphere, and thereafter they are further finely crushed andclassified or divided to be equal to or less than 100 μm in a maximumparticle diameter, to be from 1 μm to 50 μm in a mean particle diameter,and more preferably to be powders within a range from 2 μm to 5 μm.

[0032] In a case where the maximum diameter of the particles exceeds 100μm or the mean diameter exceeds a range from 1 μm to 50 μm, they cannotbe dissolved into drink water, and they are deposited or settled,therefore it is impossible to show their function. In a case where themean particle diameter is less than 1 μm, they absorb moisture, so as tobe solid. It is difficult to handle.

[0033] However, depending upon the condition of use, it is also possibleto use the burned shells without crushing. If they are crushed intominute particles, they can be dissolved into water. Therefore the effectis large; however the effect disappears in a short time. To maintain theeffect for a long time, it is preferable that the burned shells are usedwithout crushing, or powders crushed into minute particles are mixedtogether with a binder, and thereafter are burned, thereby forming intoa predetermined form.

[0034] The anti-bacteria agent manufactured in the manner mentionedabove is effective to Esherichia coli, such as O-157 or the like, foodpoisoning bacteria, such as Staphylococcus aureus, Psedomonasaeruginosa, Eumycetes, salmonella, enteritis vibrio or the like, andvirus.

[0035] As a concrete use of the anti-bacteria agent according to thepresent invention, it can be used as an additive into a food, such as aboiled fish paste (called kamaboko in Japan) or the like, drink water,hand-washing water, and dental materials, such as an artificial tooth orthe like. In addition, it can be used to be put into a pot for home useas anti-bacteria powders pack, or to disinfect drink water for disasteror emergency time. It can be used to be added into a sheet which is forcleaning and wiping, a paper diaper, a wall paper, or buildingmaterials, as an anti-bacteria function additive. As other methods foruse, the anti-bacteria agent itself can be made into a ceramic, orsterilizing apparatus or device can be produced with use of theanti-bacteria function thereof.

[0036] The anti-bacterial agent according to the present invention showsa higher anti-bacteria property than that of tea catechin or oystershell. Therefore, it is characterized that the anti-bacteria effect canbe obtained with a little amount, and that the effect is maintained fora long time. For example, an addition amount for drink water or forother objects to be disinfected is sufficient to be 0.025 weight % withrespect to the weight of drink water or other objects. An amount morethan this may be added depending upon the condition of use. Theanti-bacteria effect can be maintained for a long time, and it isconfirmed that the effect can be maintained more than 48 hours.

EXAMPLES

[0037] Manufacture of Anti-Bacteria Agent:

[0038] Shells of surf clams were dried, and thereafter pre-crushed intoabout 2 mm - 3 mm in size. 500 g thereof were put into an autoclaveequipped with a stirrer, which was filled with nitrogen gas and had acapacity of 2 liters. A temperature was started to be increased whilethe stirrer was slowly operated. This was continued until thetemperature reached 900° C. After the shells were burned for five (5)minutes at 900° C., the heating was stopped. Then, the shells were leftfor cooling within the flow of nitrogen gas until the inside of theautoclave turned back to the room temperature.

[0039] After being left for cooling, the burned shell powders were takenout from the autoclave, and they were further crushed by means of amortar. The particles being equal to or less than 50 μm were selected bya selector, thereby manufacturing the anti-bacteria agent according tothe present invention.

[0040] The ingredient concentration of this anti-bacteria agent is shownon the following Table 1 (by an analysis according to soil nutrimentanalyzing method made by Yamagata-ken Rikagaku-Bunseki (physics andchemistry analysis) Center: Yama-Bun-Se No. 778). TABLE 1 MeasuredConcentration (wet Minimum Value of Ingredient weight %) DectectionMagnesium 0.04 Phosphor Bronze 0.02 Potassium 0.07 calcium 25. Manganese0.01 Iron 0.07 Copper Not detected 0.01 Zinc Not detected 0.01Molybdenum Not detected 0.01

[0041] Charcoal of bamboo crushed and adjusted to be particles equal toor less than 50 μm, in the same manner as mentioned above, separately,was mixed with the above-mentioned anti-bacteria agent made from surfclams at a weight ratio 1:1, thereby manufacturing the anti-bacteriaagent according to another embodiment.

[0042] Further, in place of surf clams, shells of oysters was used to beburned and crushed in the same manner as mentioned above, therebymanufacturing oyster shell powders.

[0043] Test Bacteria:

[0044] Three kinds, i.e., Esherichia coli ATCC 8739, Staphylococcusaureus ATCC 6538, and Psedomonas aeruginosa ATCC 9027) were used, andcultured, on a culture medium, such as a DD checker for general bacteriaof blood agar flat plate, under a culturing condition for 18 hours at37° C.

[0045] Testing Method:

[0046] Each of the anti-bacteria agents manufactured was dissolved intodistilled water and adjusted to be at a predetermined concentration.Then each of the above-mentioned test bacteria was added to thedistilled water into which the anti-bacteria agent was dissolved, so asto be about 106 pieces/ml.

[0047] After each bacteria was added, it was well stirred and left stillat the room temperature. After a predetermined time, it was sampled tobe measured on numbers (pieces/ml) of the cultured bacteria.

Example 1

[0048] With use of a distilled-water solution (1 weight %, 0.5 weight %,0.1 weight %, and 0.05 weight %) of the anti-bacteria agent made fromsurf clams and manufactured in the manner mentioned above, thedisinfecting effects were examined on each of Esherichia coli,Staphylococcus aureus, and Psedomonas aeruginosa. The result is shown inTable 2.

Example 2

[0049] In the same manner as in Example 1 mentioned above, except thatthe mixed anti-bacteria agent between surf clams and bamboo charcoal(weight ratio: 1:1) was used in place of the anti-bacteria agent madefrom surf clams, the disinfecting effects of the mixed anti-bacteriaagent were examined. The result is also shown in Table 2.

Example 3

[0050] In the same manner as in Example 1 mentioned above, except thatan anti-bacteria agent made from oyster shells was used in place of theanti-bacteria agent made from surf clams, the disinfecting effects ofthe anti-bacteria agent were examined. The result is also shown in Table2. TABLE 2 Concentration Staphylococcus Psedomonas Examples of Anti-Esherichia coli aureus aeruginosa and bacteria Agent After 15 After 24After 15 After 48 After 15 After 24 Comparison (W %) minutes hoursminutes hours minutes hours Example 1 1% <20 <20 <2 <2 <2 <2 0.5% <20<20 — — — — 0.1% <20 <20 1.9 × 10² 60 <2 <2 0.05% <20 <20 — — — —Example 2 1% <20 <20 2.0 × 10² 80 <2 <2 0.5% <20 <20 — — — — 0.1% <20<20 2.0 × 10⁴ 2.0 × 10² <2 <2 0.05% 4.0 × 10³ <20 — — — — Comparison 1%<20 <20 40 2 <20 2 1 0.5% 6.4 × 10² <20 — — — — 0.1% 2.5 × 10³ 2.5 × 10⁶4.0 × 10⁵ 5.2 × 10⁵ 2.2 × 10² <1 0.05% 2.5 × 10⁵ 1.2 × 10⁵ — — — —Reference: 6.0 × 10⁵ 4.0 × 10⁵ 4.0 × 10⁵ 3.6 × 10⁵ 8.0 × 10⁵ 4.0 × 10⁶Distilled water

[0051] As is apparent from the test results shown in Table 2, theanti-bacteria agent made from surf clams achieved a sufficientdisinfecting effect even in a low concentration thereof, i.e., 0.05%.The effect was maintained not only after 24 hours, but also after 48hours. With respect to the oyster anti-bacteria agent, the effect can beobtained in the concentration of 1%. Accordingly, it can be said thatsurf clam is the most effective.

Example 4

[0052] The concentration of the distilled-water solution of theanti-bacteria agent made from surf clams was decreased to be lower thanin Example 1 (i.e., 0.025 weight %, and 0.005 weight %), thedisinfecting effects were examined on each of Esherichia coli andStaphylococcus aureus. The result is shown in Table 3.

Example 5

[0053] In the same manner as in Example 4 mentioned above, except thatthe anti-bacteria agent made from oyster shells was used in place of theanti-bacteria agent made from surf clams, the disinfecting effects wereexamined. The result is also shown in Table 3. TABLE 3 StaphylococcusConcentration Esherichia coli aureus of Anti- (2.0 × 10⁵) (2.0 × 10⁵)Examples and bacteria Agent After 1 After 24 After 1 After 48 Reference(W %) hours hours hours hours Example 3 0.025% 4 <2 20 <2 — — — — 0.005%1.6 × 4.0 × 2.4 × 2.0 × 10⁵ 10⁴ 10⁴ 10² — — — — Example for  0.05% — —4.0 × <2 Reference 10² — — — — —  0.01% — — 4.8 × 6.0 × 10⁴ 10² — — — ——

[0054] From the test results in Table 3, it is apparent that theanti-bacteria agent made from surf clams achieves a sufficientdisinfecting effect even in a further lower concentration thereof, i.e.,0.025%.

[0055] Next, the further test of the disinfecting effects is conductedon the anti-bacteria agent made from surf clams according to the presentinvention (surf clam calcium powder), calcium bicarbonate, scallopshells, clam shells, turban shells, snail shells or oyster shells inYamagata-ken Rikagaku-Bunseki (physics and chemistry analysis) Center.The results are shown in the following Tables 4 through 16. TABLE 4(Sample: Surf clam calcium power (Present Invention)) Number of GeneralGroup Number of bacteria (/ml), Esherichia coli, Standard agar culturedesoxycol acid salt medium method culture medium method Testing Liquid  120.  0. (Miscellaneous drainage of hot spring containing sample 0.1%W/V, sampled after 10 minutes) Reference Liquid 11,000. 410.(Miscellaneous drainage of hot spring)

[0056] TABLE 5 (Sample: Calcium bicarbonate (Burned at 1,000° C.))Number of General Group Number of bacteria (/ml), Esherichia coli,Standard agar culture desoxycol acid salt medium method culture mediummethod Testing Liquid (River    56.  0. water containing sample 0.1%W/V, sampled after 10 minutes) Reference Liquid 17,000. 57. (Riverwater)

[0057] TABLE 6 (Sample: Calcium bicarbonate (Not Burned)) Number ofGeneral Group Number of bacteria (/ml), Esherichia coli, Standard agarculture desoxycol acid salt medium method culture medium method TestingLiquid (River 18,000. 26. water containing sample 0.1% W/V, sampledafter 10 minutes) Reference Liquid 17,000. 57. (River water)

[0058] TABLE 7 (Sample: Dried scallop) Number of General Group Number ofbacteria (/ml), Esherichia coli, Standard agar culture desoxycol acidsalt medium method culture medium method Testing Liquid (River   720. 0. water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

[0059] TABLE 8 (Sample: Non-burned scallop) Number of General GroupNumber of bacteria (/ml), Esherichia coli, Standard agar culturedesoxycol acid salt medium method culture medium method Testing Liquid(River 4,100. 62. water containing sample 0.1% W/V, sampled after 10minutes) Reference Liquid 3,100. 56. (River water)

[0060] TABLE 9 (Sample: Dried Clam) Number of General Group Number ofbacteria (/ml), Esherichia coli, Standard agar culture desoxycol acidsalt medium method culture medium method Testing Liquid (River   630. 0. water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

[0061] TABLE 10 (Sample: Non-burned Clam) Number of General Group Numberof bacteria (/ml), Esherichia coli, Standard agar culture desoxycol acidsalt medium culture culture medium method Testing Liquid (River 3,700.48. water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

[0062] TABLE 11 (Sample: Dried Turban shell) Number of General GroupNumber of bacteria (/ml), Esherichia coli, Standard agar culturedesoxycol acid salt medium method culture medium method Testing Liquid(River   720.  0. water containing sample 0.1% W/V, sampled after 10minutes) Reference Liquid 3,100. 56. (River water)

[0063] TABLE 12 (Sample: Non-burned Turban shell) Group Number Number ofGeneral of Esherichia coli, bacteria (/ml), desoxycol acid Standard agarculture salt culture medium method medium method Testing Liquid 3,700.54. (River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

[0064] TABLE 13 (Sample: Dried Snail shell) Group Number Number ofGeneral of Esherichia coli, bacteria (/ml), desoxycol acid Standard agarculture salt culture medium method medium method Testing Liquid   650. 0. (River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

[0065] TABLE 14 (Sample: Non-burned Snail shell) Group Number Number ofGeneral of Esherichia coli, bacteria (/ml), desoxycol acid Standard agarculture salt culture medium method medium method Testing Liquid 3,600.47. (River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3.100. 56. (River water)

[0066] TABLE 15 (Sample: Dried Oyster shell) Group Number Number ofGeneral of Esherichia coli, bacteria (/ml), desoxycol acid Standard agarculture salt culture medium method medium method Testing Liquid   620. 0. (River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

[0067] TABLE 16 (Sample: Non-burned Oyster shell) Group Number Number ofGeneral of Esherichia coli, bacteria (/ml), desoxycol acid Standard agarculture salt culture medium method medium method Testing Liquid 3,700.62. (River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

[0068] From the above Tables 4 through 16, it is apparent that shellpowders of surf clam were inferior to calcium bicarbonate in adisinfecting power or effect; however they were superior to shellpowders of other shells. Also, including other shells, it is apparentthat a remarkable difference occurs between the burned one and theunburned one in a disinfecting power or effect.

[0069] Hereinafter, explanation will be given on embodiments forobtaining freshwater from sea water, for purifying river water, and forwashing agricultural products, by referring to FIGS. 1 through 3.

[0070]FIG. 1 is a block diagram for obtaining freshwater from sea water.First, sea water is pumped up by means of a pump into a reservoir tank.

[0071] Next, at a lower side of the reservoir tank a separation tank isprovided, which is divided into the first side chamber and the secondside chamber through a reverse permeable membrane, and sea water withinthe reservoir tank is sent into the first side chamber through aconduit.

[0072] A pressure of water head acts on the sea water in the first sidechamber, and freshwater is permeated through the reverse permeablemembrane into the second side chamber, with being removed NaCl etc.therefrom.

[0073] The freshwater in the second side chamber permeates through acolumn which is filled with the anti-bacteria agent which is obtained byburning shells, such as surf clams or the like, while it is disinfected.Finally, it is supplied to a desired positions or places.

[0074]FIG. 2 (A) shows a method for purifying river water, and FIG. 2(B) shows a perspective view of a net to be provided or positioned on abed of river. In this embodiment, burned shells of such as surf clams orthe like, are filled in the net, and the net is provided or positionedon a bed of river.

[0075] In a case of this embodiment, from a view point of maintaining apurification effect for a long time, it is preferable that burned shellsare not crushed finely. Since the burned shells come to be porous, thespecific surface area thereof is large, therefore, bacteria whichdecomposes organic matters is easily propagated thereon. When riverwater comes to be high in the acidity thereof, contents of shells aredissolved into river water, thereby achieving an effect to keep pH ofriver water constant.

[0076]FIG. 3 (A) shows a condition of washing agricultural products, andFIG. 3 (B) shows a rinsing condition after washing. In this embodiment,within a container filled with a synthetic detergent, a basket(s) inwhich agricultural products are received is (are) dipped. Next, thebasket is taken out therefrom, and water which is contacted with theburned shells mentioned above is sprinkled on the agricultural productsby means of a shower, thereby removing the synthetic detergent attachedto the surface of the agricultural products.

[0077] As is fully mentioned above, the anti-bacteria agent according tothe present invention, is manufactured by burning shell powders of surfclams etc. in an atmosphere of inactive gas, and it shows a highdisinfecting effect or power.

[0078] In more detail, it shows a disinfecting effect upon Esherichiacoli, such as O-157 or the like, food poisoning bacteria, such asStaphylococcus aureus, Psedomonas aeruginosa, Eumycetes, salmonella,enteritis vibrio or the like, and further virus, in a low concentrationthereof, and it maintains the disinfecting function for a long time.

[0079] Further, shell powders of surf clams etc. are a natural material,which mainly contains calcium which is used also as an additives intofoods, therefore it is possible to provide an anti-bacteria agent safefor the human body, and it does not contaminate air, waste water andsoil, even when it must be processed to be disposed.

[0080] Furthermore, with use of the anti-bacteria agent according to thepresent invention, shells of surf clams etc. can be used effectively fordesalination of sea water, purifying river water, or for washingagricultural products, etc., though they are conventionally embarrassingthings as a disposal.

What is claimed is:
 1. An anti-bacteria agent which is obtained byheating a shell in an atmosphere of inactive gas and burning said shellunder the temperature which finally reaches 700° C. - 2,500° C.
 2. Ananti-bacteria agent as defined in claim 1, wherein said shell is that ofa surf clam.
 3. An anti-bacteria agent as defined in claim 1, whereinsaid shell is that of any one of an oyster, a scallop, a clam, a turbanshell and a snail.
 4. An anti-bacteria agent as defined in claim 1,wherein said shell is crushed before or after burned.
 5. Ananti-bacteria agent as defined in claim 4, wherein said shell aftercrushed has a maximum particle diameter equal to or less than 100 μm,and has a mean particle diameter from 1 μm to 50 μm.
 6. An anti-bacteriaagent as defined in claim 1, which includes a powder obtained bycrushing charcoal of bamboo.
 7. A desalination method of sea water,comprising the following steps of: obtaining freshwater from sea waterthrough any one of a reverse permeable membrane method, a distillationmethod, a refrigeration method and an electric dialysis method; andcontacting said freshwater with an anti-bacteria agent defined in anyone of claims 1 to
 6. 8. A purification method of river water,comprising the following steps of: filling a net with an anti-bacteriaagent defined in any one of claims 1 to 6; and laying said net in river.9. A washing method of agricultural products, comprising the followingsteps: washing agricultural products, including vegetables and fruits,with a synthetic detergent; and rinsing said agricultural productswashed with water which is contacted with an anti-bacteria agent definedin any one of the claims 1 to 6.